Not applicable.
Not applicable.
The present invention relates to bathtubs and in particular to mechanisms for controlling the drainage of water from bathtubs.
There is a renewed interest in styling from past eras, such as the Victorian and Elizabethan periods. One such retro-style design is a free-standing bathtub located centrally in a bathroom. See e.g. U.S. Pat. No. D235,106.
Such designs support tubs on legs so that they are positioned sufficiently far away from a bathroom wall so that the tub is accessible from any side. However, this requires the plumbing conduits for filling and draining the bathtub to extend up from the floor and be exposed, rather than hidden in the wall. Thus, it is important to limit the amount of exposed plumbing to reduce cost, for aesthetic appearance, and for other reasons.
A standard feature of most bathtubs is an overflow drainage system which prevents the bathtub from being overfilled to the point that water will flow over the sides of the bathtub and onto the floor. Typical overflow systems provide an opening through an end wall near the top foot end of the bathtub, which is coupled to a waste drain via a lateral conduit. For a free-standing bathtub, this lateral conduit would be exposed, thereby adding to the cost of the bathtub and the adverse aesthetics.
One overflow mechanism designed for such a free-standing bathtub is disclosed in U.S. Pat. No. 851,513. This mechanism avoids the need for a separate overflow. It has an exposed standpipe coupled below the floor to a waste drain leading from the bottom of the bathtub. The standpipe houses a tubular valve that is operated by a lift knob extending up through the top of the standpipe. When the lift knob is completely lowered, the valve stem prevents water from exiting the bottom of the standpipe so that the bathtub can be filled (thereby eliminating the need for a drain stopper).
As the bathtub is filled, water passes through the waste drain and fills the standpipe outside of the valve tube. Because water always finds its own level, the water in the bathtub is at the same height as the water in the standpipe. When the water in the standpipe reaches the top of the valve tube (or alternatively holes in the valve tube), water drains down through the center of the valve stem. In this way, the water cannot overflow the bathtub and there is no need for a separate overflow port formed in a side wall of the bathtub.
However, in this early design as the water level rises in the tub more and more hydrostatic pressure acts against the side of the valve tube and along its sides. This causes a number of problems. For example, the lift knob becomes more difficult to raise and water is prone to leak past the valve seat. Further, this valve can be quite noisy.
There is still a need to improve the functional aspects of overflow mechanisms for such bathtubs.
In one aspect the invention provides a drain stop and overflow mechanism for a basin having a water drain opening. There is a standpipe which is connectable at a lower end to a waste water line through a drain valve seat. There is also a drainpipe connectable at one end to the water drain opening of the basin and at another end to the standpipe.
A sleeve is positioned within the standpipe and extends upward to a selected overflow height. The sleeve has a lesser outer diameter than an inner diameter of the standpipe so that a passage exists therebetween. The sleeve also has a bottom end in fluid communication with the drainpipe, and, when the drain valve seat is not closed, also the waste water line.
There is also a plunger disposed within the sleeve and having a lower valve head and a stem extending upwardly therefrom to a lift element positioned over the standpipe. The valve head is removably positionable on the drain valve seat. A by-pass route connects a lower end of the passage and the waste water line.
Lifting the lift element can cause the valve head to move off of the drain valve seat. Further, when the valve head is on the drain valve seat water can rise within the sleeve, and then pass into the passage and then down past the drain valve seat into the waste water line.
In preferred forms, the standpipe is attached to the basin by a bracket, and the lift element is a knob that can be raised and then pivoted to engage a stop to prevent downward movement of the plunger.
Thus, the present invention provides an overflow and stopper mechanism that is particularly well-suited for use with a free-standing bathtub. It also can be used with pedestal lavatories and other basins.
It eliminates the need for an exposed a drain plug and also eliminates the need for a separate overflow hole and drainage system. This therefore reduces cost and provides a more appealing fixture. Additionally, the water column within the plunger sleeve acts to seat the valve head against the valve seat so that the mechanism is not prone to leakage. Moreover, the plunger stem can be a narrow rod such that it encounters little or no side force from the water leaving the basin.
The foregoing and other advantages of the invention will appear from the following description. In this description reference is made to the accompanying drawings which form a part hereof and in which there is shown by way of illustration preferred embodiments of the invention. These embodiments do not represent the full scope of the invention. Thus, the claims should be looked to in order to ascertain the scope of the invention.